1. Field of the Invention
The present invention relates to a space heater that has an air cleaning function and that halts combustion at a burner when a combustion abnormality has occurred.
2. Related Background Art
There is, as an example, a well known gas space heater wherein a thermocouple is provided near a burner and combustion at the burner is controlled by monitoring the thermoelectromotive force generated by the thermocouple, and wherein, when the thermoelectromotive force is reduced to a predetermined reference value or lower, due to incomplete combustion at the burner or a misfire, combustion at the burner is forcibly halted. Furthermore, a gas space heater is proposed wherein such a reference value is designated based on the thermoelectromotive force generated by the thermocouple when the burner is in a stable combustion state, thereby preventing the erroneous halting of combustion at the burner when incomplete combustion or a misfire does not actually occur (e.g., Japanese Patent Laid-Open Publication No. Hei 05-223248).
Furthermore, a gas space heater having an air cleaning function has been developed in order to improve the convenience afforded users.
For a space heater having an air cleaning function, a heating fan for supplying air for combustion to a burner and an air cleaning fan for supplying air to an air cleaner must be separately provided in order to independently control the flow rate of the air supplied to the burner and the flow rate of the air supplied to the air cleaner. In addition, as the sizes of space heaters are reduced, there are cases wherein separate air intakes for the heating fan and for the air cleaning fan are located near each other, and cases wherein a single, common air intake is provided for both the heating fan and the air cleaning fan.
A space heater having an air cleaning function selectively performs, in a “synchronous operating mode”, both heating and air cleaning, or performs, in an “independent heating mode”, only heating. However, in both the “synchronous operating mode” and the “independent heating mode”, combustion at the burner must be monitored.
For a space heater wherein the air intake for a heating fan and the air intake for an air cleaning fan are located near each other, and for a space heater wherein a single air intake is provided for the two fans, the present inventors found that even when a reference value for an abnormal combustion was designated while the burner was in a stable combustion state, sometimes a combustion abnormality was erroneously detected and combustion at the burner was halted.
It is, therefore, one objective of the present invention to provide a space heater that has an air cleaning function and that can, by monitoring the combustion state of a burner, prevent combustion at the burner from being halted due to the erroneous detection of a combustion abnormality.